Asthma is a chronic airway inflammatory disease and affects nearly 155 million individuals worldwide. The population of asthma sufferers has been documented since 1970 and has increased continuously since then. A survey in 1994 by the U.S. Department of Health and Human Services identified over 12 million Americans suffering from asthma, almost 5 million of them under the age of 18. In addition, a patient's condition becomes more serious over time, resulting in increased hospitalization and possibly death.
Inheritance plays a strong role in some allergic diseases, including asthma. People whose relatives suffer from asthma are also at high risk of asthma. However, if allergic factors are reduced or removed early, it may possibly prevent the development of asthma. Many approaches have been proposed to determine if there are any allergen-specific IgE antibodies in the serum, but traditional IgE tests are limited to specific allergens and cannot detect asthma at such a low sensitivity. In addition, the preferred age for testing is above three years old and 6-8 c.c. of blood is required, thus limiting the usefulness of this test.
Another possible test for asthma would involve determining an individual's genetic predisposition for asthma. Genotypic diversity is assumed to underlie the heritable phenotypic differences observed as variations in drug response, susceptibility to disease, and other complex traits. Single Nucleotide Polymorphisms (SNPs) are the most common genetic variation and are of great value to biomedical research and in developing pharmacy products. SNPs make up 90% of all human genetic variations and occur every 100 to 300 bases along the human genome. Because SNPs do not change dramatically from generation to generation, following them during population studies is straightforward.
What is needed in the art is a method of identifying susceptibility to asthma and infection, which can be used to identify individuals with increased disease susceptibility even before disease is manifest, and thus allow those individuals to take measures to prevent disease.